The present disclosure relates to subject matter contained in priority Japanese Patent Application No. 2001-71749, filed on Mar. 14, 2001.
1. Field of the Invention
The present invention relates to a method for connecting a compressor having a built-in electric motor to an electric-power supply wiring that are suitable for mobile structures such as vehicles, a connection device used for the connection method, and a compressor with a built-in electric motor using the method and the connection device.
2. Description of Related Art
In a vehicle driven only by an engine, a compressor driven by the engine is used for air-conditioning the vehicle compartment, and the compressor is mounted alongside the engine.
An electric vehicle or a hybrid vehicle having both an engine and an electric motor and traveling by use of one of them according to conditions has been practically used for going on public roads. Between the two kinds of vehicles, most of those going on public roads are the hybrid vehicle, and air-conditioning of the compartments of such a vehicle is made by a refrigerating compressor driven by the engine in the same way as conventional engine-driven vehicles.
It is proposed for hybrid vehicles that the engines should be shut off while they are temporarily stationary at a place such as a traffic light. When the proposal is followed with a vehicle where a compressor driven by the engine is used, air-conditioning also stops each time when the vehicle stops, causing problem for the driver and passengers in the compartment in summer and winter seasons, and especially in regions with extremely cold or hot climate.
Consequently, an idea of using a compressor driven by an electric motor comes out. Compressors driven by electric motors include maintenance-free compressors integral with electric motors mass-produced and used for air-conditioning of houses, and it is desirable to use such compressors for electric vehicles.
The present inventors made various examinations and studies to find that compressors with built-in electric motors originally designed for air conditioning indoors have not very high sealing capability against water including rain water. This is because such compressors are stored within outdoor units and installed outdoors. In such compressors, an inside-outside connection terminal is arranged at the case that accommodates an electric motor and a compressing mechanism. A connection portion at the inside-outside connection terminal where connection is made between connection pins for external wiring and connection terminals of external wiring is covered by a cover made of synthetic resin, and the cover is screwed to the case. Sealing is made only at a portion where an opening edge of the cover and the case are tightly contacted with each other by the screwing. For improved sealing effect, an appropriate number of circular projections are arranged on a face of the opening edge of the cover that contacts with the case. However, this kind of sealing is considered insufficient for installing a compressor within an engine compartment of a vehicle that is prone to be subjected to water or oil.
Further, the connection terminal is, for example, a type called a fast-on terminal, which is a relatively small female type terminal having curl edge portions at both sides of a front face of a back plate. The connection terminal is connected by fitting to a connection pin for external connection having at its one side a plate, called a flag-type pin. Compressors with built-in electric motors have three, five or other number of the connection portions described above depending on the type of drive or control. Three connection portions are for connection to a 3-phase power supply, and five connection portions are for connection to 3-phase power supply and a sensor for detecting temperature of an electric motor.
Fitting the connection terminal to the connection pin for external wiring is made by pressing the plate of the connection pin into between the back plate and the end portions of the curl edge portions opposing the back plate, so that the connection pin for external wiring is pressed and set into narrow portions formed between the connection pins and the plate. In this constitution, the fitting is too tight to make the fitting manually while holding the connection pins for external wiring and the connection terminals by hands. Accordingly, the connection work requires tools for holding and handling the connection terminal to fit it to the connection pin for external wiring, and this is troublesome and time consuming work.
A main object of the present invention is to provide a connection method with which connection work of connection terminals including sealing is easily conducted with excellent workability, a connection device used for the connection method, and a compressor with a built-in electric motor using the connection method and the connection device. It is also an object of the invention to provide high sealing capability, required for vehicles, of the compressor integral with an electric motor.
In order to achieve the above objects, a method according to the invention for connecting a compressor having a built-in electric motor to external wiring is constituted as follows. A compressing mechanism and an electric motor that drives the compressing mechanism are accommodated in a case. Electric power to the electric motor is supplied through connection between a plurality of connection pins, projecting from an inside-outside connection terminal arranged at the case, provided for connection to external wiring, and connection terminals of external wiring. The plurality of connection terminals are covered with a housing in a waterproof state. The terminals are collectively treated by handling the housing, so that an opening of the housing is put over the inside-outside terminal and fixed to the case while connecting the plurality of connection terminals to the connection pins for external wiring through the opening of the housing. The opening is tightly contacted, directly or along with a seal member in between, to the case for conducting sealing between them.
A connection device for achieving the connection method described above is provided with a lead wire for connection to external wiring, a plurality of connection terminals that are connected to connection pins for external wiring and that are arranged at the tip of the lead wire. The device further including a housing that collectively protects the connection terminals and covers them with a waterproof portion of the housing (except its opening). The device also including a fixing device for fixing the housing to an outer face of the case, and a seal portion for creating a seal between the opening of the housing and the case.
In a compressor with a built-in electric motor according to the invention using the connection method and connection device described above, a compressing mechanism and an electric motor that drives the mechanism are accommodated in a case and used for air-conditioning a mobile structure compartment. Electric power for the motor is supplied from external wiring connected to a plurality of connection pins. The pins project from an inside-outside connection terminal arranged at the case and that provide a connection to the external wiring. The compressor according to the invention is further provided with a lead wire unit and a fixing device. The lead wire unit has a housing that collectively protects a plurality of connection terminals arranged at the tips of lead wires and is connected to the connection pins for external wiring. The housing covers the connection terminals in a waterproof manner, allowing connection of the connection terminals to the connection pins through an opening of the housing. The fixing device fixes the housing to an outer face of the case. The compressor also has a seal portion to seal the opening of the lead wire unit to the case.
While novel features of the invention are set forth in the preceding, the invention, both as to organization and content, can be further understood and appreciated, along with other objects and features thereof, from the following detailed description and examples when taken in conjunction with the attached drawings.